Digitala Vetenskapliga Arkivet

Change search
Refine search result
1234567 1 - 50 of 51065
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    A Asif, Farazee M
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Circular Manufacturing Systems: A development framework with analysis methods and tools for implementation2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The society today lives on the philosophy of ‘take-make-use-dispose.’ In the long run, this is not sustainable as the natural resources and the waste carrying capacity of the earth are limited. Therefore, it is essential to reduce dependency on the natural resources by decoupling the growth from the consumption. In this venture, both the society and the manufacturing industry have a vital role to play. The society needs to shift towards Circular Economy that rests upon the philosophy of ‘take-make-use-reuse’ and the manufacturing industry has to be a major stakeholder in this shift. Despite being proven to be both economically and environmentally beneficial, successful examples of circular systems are few today. This is primarily due to two reasons; firstly, there is a lack of systemic and systematic approach to guide industries and secondly, there is a lack of analysis methods and tools that are capable of assessing different aspects of circular manufacturing systems. Taking on to these challenges, the objective of this research is to bring forward a framework with methods and decision support tools that are essential to implement circular manufacturing systems. The initial conceptual framework with the systemic approach is developed based on extensive review and analysis of research, which is further adapted for industrial implementation. Systematic analysis methods, decision support and implementation tools are developed to facilitate this adaptation. This development has been supported by four cases from diverse manufacturing sectors. Behind each decision support tool, there are analysis methods built upon mainly system dynamics principles. These tools are based on simulation platforms called Stella and Anylogic. Among other things, these tools are capable of assessing the performance of closed-loop supply chains, consequences of resource scarcity, potential gains from resource conservation and overall economic and environmental performance of circular manufacturing systems.

    Download full text (pdf)
    fulltext
  • 2.
    A Asif, Farazee M
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Rashid, Amir
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Bianchi, Carmine
    University of Palermo (ITALY) Faculty of Political Sciences - Department of International Studies .
    Nicolescu, Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Performance analysis of the closed loop supply chain2012In: Journal of Remanufacturing, ISSN 2210-4690, Vol. 2, no 4Article in journal (Refereed)
    Abstract [en]

    Purpose

    The question of resource scarcity and emerging pressure of environmental legislations has brought a new challenge for the manufacturing industry. On the one hand, there is a huge population that demands a large quantity of commodities; on the other hand, these demands have to be met by minimum resources and pollution. Resource conservative manufacturing (ResCoM) is a proposed holistic concept to manage these challenges. The successful implementation of this concept requires cross functional collaboration among relevant fields, and among them, closed loop supply chain is an essential domain. The paper aims to highlight some misconceptions concerning the closed loop supply chain, to discuss different challenges, and in addition, to show how the proposed concept deals with those challenges through analysis of key performance indicators (KPI).

    Methods

    The work presented in this paper is mainly based on the literature review. The analysis of performance of the closed loop supply chain is done using system dynamics, and the Stella software has been used to do the simulation. Findings The results of the simulation depict that in ResCoM; the performance of the closed loop supply chain is much enhanced in terms of supply, demand, and other uncertainties involved. The results may particularly be interesting for industries involved in remanufacturing, researchers in the field of closed loop supply chain, and other relevant areas. Originality The paper presented a novel research concept called ResCoM which is supported by system dynamics models of the closed loop supply chain to demonstrate the behavior of KPI in the closed loop supply chain.

  • 3.
    A Monfared, Behzad
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Design and Construction of a Small Ammonia Heat Pump2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In view of the fact that most of the synthetic refrigerants, in case of leakage or release, are harmful to the environment by contributing in global warming or depleting stratospheric ozone layer, many research works have been done recently to find alternative refrigerants posing no or negligible threat to the environment. Among alternative refrigerants, ammonia, a natural refrigerant with zero Global Warming Potential (GWP) and Ozone Depletion Potential (ODP), can be a sensible choice.Although ammonia has been used for many years in large industrial systems, its application in small units is rare. In this project a small heat pump with about 7 kW heating capacity at -5 °C and +40 °C evaporation and condensation temperatures is designed and built to work with ammonia as refrigerant. The heat pump is expected to produce enough heat to keep a single-family house warm in Sweden and to provide tap hot water for the house. After successful completion of this project, it is planned to install the heat pump in a house to test it throughout a heating season to study its performance in real working conditions.Since ammonia is flammable and toxic in high concentrations, the refrigerant charge is tried to be kept low in the heat pump to reduce the risk of fire or poisoning in case of unwanted release of refrigerant to the surroundings. The compact design of the heat pump helps reducing the refrigerant charge. Besides, considering the limited space normally reserved for installation of a heat pump in a house, the compact design of the heat pump is necessary.

    Download full text (pdf)
    B A Monfared 2010_Design and Construction of a Small Ammonia Heat Pump_MSc Thesis
  • 4.
    A Monfared, Behzad
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Magnetic Refrigeration for Near Room-Temperature Applications2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Refrigeration plays a crucial role in many different sectors and consumes about 17% of the electricity produced globally. This significant energy consumption implies large share of refrigeration in primary energy consumption and other environmental impacts. In addition to the environmental impacts associated with energy consumption, the vapor-compression systems contribute in global warming due to the release of their gaseous refrigerants into the atmosphere. As an alternative technology for near room-temperature applications, magnetic refrigeration is proposed by some researchers to eliminate the release of gaseous refrigerants into the atmosphere and to reduce the energy consumption. This thesis is a compilation of a number of studies done on magnetic refrigeration for room-temperature applications.

    In the first study, the environmental impacts associated to magnetic refrigeration are looked at closely through a life cycle assessment. The life cycle assessment indicates that because of the environmental burdens related to the rare-earth materials used in magnetic refrigeration, the reduction in the environmental impacts is not guaranteed by switching to magnetic refrigeration technology. Accordingly to avoid the extra environmental impacts the magnetic refrigeration systems should use magnetic materials frugally, which requires an optimized design. In addition, operation with higher efficiency compared to vapor-compression systems is necessary to have environmental advantages, at least in some impact categories.

    A practical method to optimize the design of magnetic refrigeration systems, e.g. to have a compact design or high efficiency, is utilizing a flexible software model, with which the effect of varying different parameters on the performance of the system can be simulated. Such a software model of the magnetic refrigeration system is developed and validated in this project. In developing the model one goal is to add to the precision of the simulated results by taking more details into consideration. This goal is achieved by an innovative way of modeling the parasitic heat transfer and including the effect of the presence of magnetocaloric materials on the strength of the field created by the magnet assembly. In addition, some efforts are made to modify or correct the existing correlations to include the effect of binding agents used in some active magnetic regenerators. Validation of the developed software model is done using the experimental results obtained from the prototype existing at the Department of Energy Technology, KTH Royal Institute of Technology.

    One of the parameters that can be modified by the developed software model is the choice of the magnetocaloric materials for each layer in a layered active magnetic regenerator. Utilizing the software model for optimizing the choice of the materials for the layers reveals that materials with critical temperatures equal to the cyclic average temperature of the layers in which they are used do not necessarily result in the desired optimum performance. In addition, for maximizing different outputs of the models, such as energy efficiency or temperature lift sustained at the two ends of the regenerators, different choice of materials for the layers are needed. Therefore, in other studies seeking to improve one of the outputs of a system, the choice of the transition or critical temperatures of the materials for each layer is an additional parameter to be optimized.

    The prototype existing at the Department of Energy Technology, KTH Royal Institute of Technology, was initially designed for replacing the vapor-compression system of a professional refrigerator. However, it could not fulfil the requirements for which it was initially designed. The aforementioned developed simulation model is used to see how much the choice of the materials, size of the particles, and number of layers can enhance the performance while the operation frequency and flow rate of the heat transfer fluid are at their optimum values. In other words, in that study the room for improvement in the performance without applying major changes in the system such as the geometry of the regenerator, which implies redesigning the whole magnet assembly, is investigated. In the redesign process the effect of binding agent and the limitations associated to different properties of it is also investigated theoretically. Nevertheless, the study did not show that with keeping the geometry of the regenerators and the currently existing magnetocaloric materials the initial goals of the prototype can be achieved.

    In the next study more flexible choice of geometries and magnetocaloric materials are considered. In fact, in this study it is investigated how much the magnetocaloric materials need to be improved so that magnetic refrigeration systems can compete with vapor-compression ones in terms of performance. For the two investigated cases, the magnetic-field dependent properties of the currently existing materials are enough provided that some other issues such as low mechanical stability and inhomogeneity of the properties are solved. Nevertheless, for more demanding design criteria, such as delivering large cooling capacity over a considerable temperature span while the magnetic materials are used sparingly, the magnetic-field dependent properties need to be enhanced, as well.

    A less explored area in room-temperature magnetic refrigeration is the subject of another study included in the thesis. In this study, solid-state magnetic refrigeration systems with Peltier elements as heat switches are modeled. Since the Peltier elements consume electricity to pump heat, the modeled systems can be considered hybrid magnetocaloric-Peltier cooling systems. For such systems the detailed transient behavior of the Peltier elements together with layers of magnetocaloric materials are modeled. The mathematical model is suitable for implementation in programing languages without the need for commercial modeling platforms. The parameters affecting the performance of the modeled system are numerous, and optimization of them requires a separate study. However, the preliminary attempts on optimizing the modeled system does not give promising results. Accordingly, focusing on passive heat switches can be more beneficial.

    Download full text (pdf)
    fulltext
  • 5.
    Aagaard, Sebastian
    Örebro University, School of Science and Technology.
    Demonstrating customer and business value through the implementation of a Design for Reliability Program2023Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    It is widely assumed within industry that implementation of a Design for Reliability (DfR) Program can reduce warranty costs, increase customer value and reduce Total Cost of Ownership (TCO) when applied within both product development and product improvement projects. DfR is the set of tools and related product development processes for improvement in the reliability of a product, over time through changes in the product design and the manufacturing process. This research activity aimed at demonstrating the customer and business value of implementing a DfR Program at Epiroc Surface Division. This wasinvestigated from the perspective of selected projects and product development activities focused on the Epiroc SmartROC D65 drilling rig, which has actively worked with the reliability tools.The study has concluded that implementing the DfR Program has yielded tangible business value. The enhanced Early-Life Reliability report now allows for better evaluation of business value. This value has primarily been derived from the ability to analyze reductions in warranty costs and improvements in Mean Time Between Events (MTBE), a subset of Mean Time between Failures (MTBF). A method has been developed to determine business value in terms of cost savings. From a customer perspective, when considering the TCO, it could be demonstrated that working actively with the reliability tools during product development positively affects the mechanical availability and productivity of the equipment resulting in TCO improvements. The primary tools employed in the study include the enhanced Early-Life Reliability report, and risk management tools employed during product development for early identification of potential failure modes.The study has concluded that the most significant opportunities for improving the DfR Program is by an increased collection of relevant data from the equipment’s useful life and not limited to the early life during the warranty period. Additionally, recording and reporting actual MTBFdata would be desirable to gain a broader perspective than what MTBE currently provides. Improving the quality and reliability of the input data used in tools like the Early-Life Reliability report would significantly enhance the output of this asset. It has been proven that the data can be utilized effectively. The enhanced version of the tool is not available for widespread use within the organization. However, once released, it could be a great opportunity to improve DfR in conjunction with the developed method for prioritizing efforts and demonstrating customer and business value.

  • 6.
    Aaltonen, Harri
    et al.
    Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland.
    Sierla, Seppo
    Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland.
    Subramanya, Rakshith
    Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland.
    Vyatkin, Valeriy
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science. Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland; International Research Laboratory of Computer Technologies, ITMO University, 197101 St. Petersburg, Russia.
    A simulation environment for training a reinforcement learning agent trading a battery storage2021In: Energies, E-ISSN 1996-1073, Vol. 14, no 17, article id 5587Article in journal (Refereed)
    Abstract [en]

    Battery storages are an essential element of the emerging smart grid. Compared to other distributed intelligent energy resources, batteries have the advantage of being able to rapidly react to events such as renewable generation fluctuations or grid disturbances. There is a lack of research on ways to profitably exploit this ability. Any solution needs to consider rapid electrical phenomena as well as the much slower dynamics of relevant electricity markets. Reinforcement learning is a branch of artificial intelligence that has shown promise in optimizing complex problems involving uncertainty. This article applies reinforcement learning to the problem of trading batteries. The problem involves two timescales, both of which are important for profitability. Firstly, trading the battery capacity must occur on the timescale of the chosen electricity markets. Secondly, the real-time operation of the battery must ensure that no financial penalties are incurred from failing to meet the technical specification. The trading-related decisions must be done under uncertainties, such as unknown future market prices and unpredictable power grid disturbances. In this article, a simulation model of a battery system is proposed as the environment to train a reinforcement learning agent to make such decisions. The system is demonstrated with an application of the battery to Finnish primary frequency reserve markets.

  • 7.
    Aardal, Karen
    et al.
    Department of Mathematics, Linköping Institute of Technology.
    Ari, Aysen
    Luleå University of Technology.
    Decomposition principles applied to the dynamic production and work-force scheduling problem1987In: Engineering Costs and Production Economics, ISSN 0167-188X, E-ISSN 1878-4011, Vol. 12, no 1-4, p. 39-49Article in journal (Refereed)
    Abstract [en]

    One of the most important problems in the production and inventory planning field, is the scheduling of production and work force in a dynamic environment. Although this problem can be formulated as a linear program, it is often quite difficult to solve directly, due to its large scale. Instead, it might be fruitful to use a decomposition approach. Decomposition, in general, means decomposing a difficult problem into several easier, or a sequence of easier problems which are later coordinated to reconstruct the original problem.In this report we discuss several possibilities of applying the most common decomposition principles, namely Benders (primal) and Datnzig-Wolfe (dual), as well as a relatively new decomposition method, called cross decomposition, to the dynamic, multiproduct production and employment planning problem. A number of special cases are also presented.

  • 8.
    Aardal, Karen
    et al.
    CORE, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
    Ari, Aysen
    Luleå University of Technology.
    On the resemblance between the Kornai-Liptak and cross decomposition techniques for block-angular linear programs1990In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 46, no 3, p. 393-398Article in journal (Refereed)
    Abstract [en]

    In this paper the resemblance is demonstrated between the master- and subproblems generated by the Kornai-Liptak algorithm and the subproblems obtained by using the cross decomposition method on linear optimization problems with block-angular structure. The significance of the similarity between these two algorithms becomes apparent considering the main disadvantage attributed to cross decomposition. In cross decomposition a master problem has to be solved from time to time since the subproblems alone do not always give a converging sequence of primal and dual solutions. But if the cross decomposition algorithm is modified in such a way that the successive primal and dual subproblem solutions are taken into consideration with equal weights, this results in the Kornai-Liptak algorithm for which convergence is guaranteed

  • 9.
    Aare, Magnus
    et al.
    KTH, Superseded Departments (pre-2005), Aeronautical and Vehicle Engineering.
    Kleiven, Svein
    KTH, Superseded Departments (pre-2005), Aeronautical and Vehicle Engineering.
    Halldin, Peter
    KTH, Superseded Departments (pre-2005), Aeronautical and Vehicle Engineering.
    Injury tolerances for oblique impact helmet testing2004In: International Journal of Crashworthiness, ISSN 1358-8265, E-ISSN 1754-2111, Vol. 9, no 1, p. 15-23Article in journal (Refereed)
    Abstract [en]

    The most frequently sustained severe injuries in motorcycle crashes are injuries to the head, and many of these are caused by rotational force. Rotational force is most commonly the result of oblique impacts to the head. Good testing methods for evaluating the effects of such impacts are currently lacking. There is also a need for improving our understanding of the effects of oblique impacts on the human head. Helmet standards currently in use today do not measure rotational effects in test dummy heads. However rotational force to the head results in large shear strains arising in the brain, which has been proposed as a cause of traumatic brain injuries like diffuse axonal injuries (DAI). This paper investigates a number of well-defined impacts, simulated using a detailed finite element (FE) model of the human head, an FE model of the Hybrid III dummy head and an FE model of a helmet. The same simulations were performed on both the FE human head model and the FE Hybrid III head model, both fitted with helmets. Simulations on both these heads were performed to describe the relationship between load levels in the FE Hybrid III head model and strains in the brain tissue in the FE human head model. In this study, the change in rotational velocity and the head injury criterion (HIC) value were chosen as appropriate measurements. It was concluded that both rotational and translational effects are important when predicting the strain levels in the human brain.

  • 10.
    Aarenstrup, Filip
    University West, Department of Engineering Science, Division of Mechanical Engineering and Natural Sciences.
    Effektivisering av informationsflödet mellan säljkontoren i orderprocessen inom Höganäs AB2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Höganäs AB is one of Sweden’s oldest companies established in 1797, the company have 1900 employees today and is one of the leading producers of metal powder in the world. From the subsidiary Höganäs Sweden AB 300,000 tonnes of metal powder was dispatched 2015. The material was sent to Höganäs customers that mainly consist of component manufacturers in the automotive, wood and other manufacturing industry.

    The purpose of this thesis is to suggest a new operational working process that will increase the efficiency of the order handling process. Throughout the investigation the present state of the process has been outlined and identified at Höganäs Sweden AB.

    Höganäs AB’s order handling process consists of many operations and interfaces that are involved to secure high delivery performance to the customers. The complexity of the process increases due to this and demands an effective communication between involved interfaces. The order handling process may vary depending on factors such as delivery terms, payment terms, transport, product, country, customs clearance and quantity. The variation of these factors makes it difficult to implement a standardized approach.

    It is valuable to Höganäs AB to streamline the process. The data recorded in the business system from the customer order is an important basis for production-, dispatch- and planning departments. The recorded data can be obtained earlier if high quality conditions are created that can increase the delivery performance and affect customer relationships positively.

    With support from the collected theory and the study that contains qualitative and quantitative primary data from Höganäs Sweden AB a new working process have been formed that excels the efficiency in the process. The new approach streamlines the overall process time by 40 percent and the overall lead time with 32 percent. In addition to the increased efficiency the number of information exchanges in the process was reduced significantly.

  • 11.
    Aarno, Daniel
    et al.
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Autonomous Systems, CAS.
    Lingelbach, F.
    Kragic, Danica
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Autonomous Systems, CAS.
    Constrained path planning and task-consistent path adaptation for mobile manipulators2005In: 2005 12th International Conference on Advanced Robotics, 2005, p. 268-273Conference paper (Refereed)
    Abstract [en]

    This paper presents our ongoing research in the design of a versatile service robot capable of operating in a home or office environment. Ideas presented here cover architectural issues and possible applications for such a robot system with focus on tasks requiring constrained end-effector motions. Two key components of such system is a path planner and a reactive behavior capable of force relaxation and path adaptation. These components are presented in detail along with an overview of the software architecture they fit into.

  • 12.
    Aarrevaara, Timo
    et al.
    Helsingfors Universitet.
    Berg, Elisabeth
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Higher Education and Research: Who should pay?2014Report (Refereed)
    Download full text (pdf)
    FULLTEXT01
  • 13.
    Aarrevaara, Timo
    et al.
    Helsingfors Universitet.
    Berg, Elisabeth
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Introduction2014In: Higher Education and Research in Academe: Who should pay?, Luleå: Luleå tekniska universitet, 2014, p. 11-17Chapter in book (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 14.
    Aarthi, A. D.
    et al.
    LKAB, Malmberget, Sweden.
    Mainali, B.
    Department of Built Environment and Energy Technology, Linnaeus University, Växjö, Sweden.
    Khatiwada, Dilip
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems.
    Golzar, Farzin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems.
    Mahapatra, K.
    Department of Built Environment and Energy Technology, Linnaeus University, Växjö, Sweden.
    Implementation of GIS-AHP Framework for the Identification of Potential Landfill Sites in Bengaluru Metropolitan Region, India2023In: 9th International Conference on Energy and Environment Research - Greening Energy to Shape a Sustainable Future, Springer Nature , 2023, p. 809-818Conference paper (Refereed)
    Abstract [en]

    Uncontrolled open dumping and burning of municipality solid waste (MSW) has resulted in soil, water, and air pollution in many urban cities in India. Landfills are the most common cost-effective solution for MSW management in many developing countries like India. However, the identification of suitable landfill sites always remains a challenging task as it involves selection of several environmental criteria set by the local authorities. The objective of this study is to identify the most potential landfill sites proposed by the Government in Bengaluru Metropolitan Region, Karnataka state, India using Geographic Information System enabled Analytical Hierarchy Process based multi-criteria evaluation technique. Several criteria and constraints as recommended by the local authorities along with the proximity to the solid waste processing plants are used to identify the potential landfill sites in the study region. The study identified three highly suitable sites (Neraluru, Gudhatti, Madivala) for landfills which are not only environmentally sustainable but also economically attractive as they are closer to the solid waste processing plants minimizing the transportation cost involved in the disposal of solid waste from the source to the final disposal sites in the study region.

  • 15.
    Aas, Gro Hanne
    Luleå University of Technology.
    Kvinneforskningspolitiske (pr)øvelser1999Licentiate thesis, comprehensive summary (Other academic)
    Abstract [no]

    Målsettingen for licentiatuppsatsen er å analysere nordisk kvinneforsknings formuleringer av forskningspolitiske felter, problemstillinger og utfordringer, og gjennom kontakt og diskusjon bidra til samarbeid, diskusjoner og offentlighet om forskingspolitikk i kvinneforskning. Arbeidet har tatt utgangspunkt i relativt nytt materiale fra Danmark, Norge og Sverige. I kap. 1 presenteres prosjektet, problemstillinger og materiale. Kapitlene 2-6 består av innledninger og artikler holdt eller skrevet i løpet av de to senaste åren. Diskusjoner om kjønn og akademia står i fokus i kap. 2 - "Universities have politics". I kap. 3, artikkelen "Gamle og nye drømmer", diskuteres et kvinneforskningspolitiske intervensjonsprosjekt som blev utført for en del år tilbake, og det antydes noen nye omdreiningspunkter for et slikt arbeid. Enkelte perspektiver utdypes i kap. 4, "Kvinneforskningens samfunnskontrakt", hvor termen "kvinneperspektiv" som forskningspolitisk term granskas krtitiskt. De to siste kapitlene tar utgangspunkt i den norske forskningsmeldingen som kom våren 1999. Ut fra tre lesestrategier forsøkes det leses muligheter for kvinneforskningspolitiske strategier. Det ses også på innholdet i regjeringens forskningspolitiske verdidebatt, og det diskuteres mulige intervensjoner i denne ut fra feministiske vitenskaps- og teknologistudier.

  • 16.
    Aasa, Ulrika
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research. Department of Community Medicine and Rehabilitation, Physiotherapy, University of Umeå, Sweden.
    Jensen, B. R.
    Sandfeld, J.
    Richter, Hans
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Lyskov, Eugene
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Crenshaw, Albert G.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    The impact of object size and precision demands on fatigue during computer mouse use2011In: Advances in Physiotherapy, ISSN 1403-8196, E-ISSN 1651-1948, Vol. 13, no 3, p. 118-127Article in journal (Refereed)
    Abstract [en]

    Prolonged computer use, especially if fatigue ensues, is associated with visual and musculoskeletal symptoms. The aim was to determine the time-course of perceived fatigue in the wrist, forearm, shoulder and eyes during a 60-min mouse task (painting rectangles), and whether object size and/or mouse use demands were of influence. Also, we investigated performance (number of rectangles painted), and whether perceived fatigue was paralleled by local muscle fatigue or tissue oxygenation. Ten women performed the task for three conditions (crossover design). At condition 1, rectangles were 45 × 25 mm, square paint cursor size 1.3 × 1.3 mm, and mousepointer movement ratio 1:26. At condition 2, the same cursor size and mousepointer movement ratio was used, but rectangles were smaller. At condition 3, the smaller rectangles were used, but the cursor size was also smaller and mousepointer movement ratio was 1:8. The results showed increased self-reported fatigue over time, with the observed increase greater for the eyes, but no change in physiological responses. Condition 2 resulted in higher performance and increased eye fatigue. Perceived fatigue in the muscles or physiological responses did not differ between conditions. In conclusion, computer work tasks imposing high visual and motor demands, and with high performance, seemed to have an influence on eye fatigue. 

  • 17.
    Aasberg, Pål
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Energilager i en överdimensioneradvindkraftspark: En linjäroptimering av batterilager i kombination medintermittenta förnybara energikällor2022Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A linear optimization has been made to examine the economic viabilityof incorporating battery storage in a wind farm in Sweden. The studyexamines a future wind farm with 10 10 MW turbines. An orographicmapping with height differences and vegetation has been used incombination with measured wind data with IEC-rated anemometersand wind direction sensors between 1997 and 2017 to create asimulated production in the windPRO software. This effect, togetherwith hourly prices from 2021 from Nord pool in SE1, SE2, SE3, SE4and in Estonia, has been used in a linear optimization in Matlab to findthe battery capacity that generates the most revenue. 3 Scenarios areinvestigated where scenario 1 is a wind farm without battery storagewhere all electricity produced is sold directly at the current price.Scenario 2 also lacks battery storage and has a power limit of 75 MWat the transformer whilst the farm still produces 100 MW. Scenario 3has a power limit of 75 MW at the transformer and the possibility ofbattery storage.

  • 18.
    Aava, Nils
    et al.
    Luleå University of Technology.
    Ericson, Ronald
    Luleå University of Technology.
    Esberg, Lars
    Luleå University of Technology.
    Belysning i bilverkstäder: förslag till belysningsplanering1979Report (Other academic)
  • 19.
    Abacar, Armando
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Optimization of Maputo Power Plant2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Electricidade de Moçambique, E.P. (EDM) is the power utility in Mozambique, responsible to generate, transport and distribute electricity all over the country. The company has three gas turbines installed at Maputo Power Plant. All units burn diesel oil and are used only for back up. Currently only the unit #2 is available for operation.

    The main constraint that EDM faces is the high operation costs due to diesel price. Hence the company is considering converting units #2 and #3 to burn natural gas, resource available locally. The country is currently exporting natural gas to the neighbouring Republic of South Africa.

    This MSc thesis project calculates the power output of all gas turbines when burning natural gas and optimizes the power plant capacity by proposing modifications of the current power turbine cycles to allow sustainable operation

    Download full text (pdf)
    fulltext
  • 20.
    Abadi, Imam
    et al.
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Hardiana, Tiara Oktavia
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Imron, Chairul
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Fitriyanah, Dwi Nur
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Jani, Yahya
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Abdullah, Kamaruddin
    Darma Persada University, Indonesia.
    Design of Adaptive Neuro-Fuzzy Inference Control Based One-Axis Solar Tracker on Battery Charging System2020In: E3S Web of Conferences, EDP Sciences, 2020, Vol. 190, p. 1-15, article id 00015Conference paper (Refereed)
    Abstract [en]

    The photovoltaic (PV) panel can produce electrical energy that is very environmentally friendly and easy to use. The use of PV panels is suitable for supplying peak loads or at night using batteries as energy storage. However, the battery needs to manage for control, and the battery can last long. The solution to battery management problems is through research about the battery charging system. The DC-DC converter used is the Single Ended Primary Inductance Converter (SEPIC) type. Voltage Control of the battery charging using Adaptive Neuro-Fuzzy Inference System (ANFIS). In the simulation of bright conditions, ANFIS controls can track the charging point set point and obtain a voltage response with a rise time of 0.0028 s, a maximum overshoot of 0.027 %, a peak time of 0.008 s, and a settling time of 0.0193 s. When charging a solar tracker, PV battery gets a 0.25 % increase compared to a fixed PV panel. PV solar tracker can follow the direction of the sun's position. The irradiation value and maximum temperature affect the input voltage and input current that enters the converter. © The Authors, published by EDP Sciences, 2020.

  • 21.
    Abadi, Imam
    et al.
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Hardiana, Tiara Oktavia
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Imron, Chairul
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Fitriyanah, Dwi Nur
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Jani, Yahya
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM), Sweden.
    Abdullah, Kamaruddin
    Darma Persada University, Indonesia.
    Design of Adaptive Neuro-Fuzzy Inference Control Based One-Axis Solar Tracker on Battery Charging System2020In: E3S Web of Conferences, EDP Sciences , 2020, p. 1-15, article id 00015Conference paper (Refereed)
    Abstract [en]

    The photovoltaic (PV) panel can produce electrical energy that is very environmentally friendly and easy to use. The use of PV panels is suitable for supplying peak loads or at night using batteries as energy storage. However, the battery needs to manage for control, and the battery can last long. The solution to battery management problems is through research about the battery charging system. The DC-DC converter used is the Single Ended Primary Inductance Converter (SEPIC) type. Voltage Control of the battery charging using Adaptive Neuro-Fuzzy Inference System (ANFIS). In the simulation of bright conditions, ANFIS controls can track the charging point set point and obtain a voltage response with a rise time of 0.0028 s, a maximum overshoot of 0.027 %, a peak time of 0.008 s, and a settling time of 0.0193 s. When charging a solar tracker, PV battery gets a 0.25 % increase compared to a fixed PV panel. PV solar tracker can follow the direction of the sun's position. The irradiation value and maximum temperature affect the input voltage and input current that enters the converter. 

  • 22.
    Abadi, Imam
    et al.
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Uyuniyah, Qurrotul
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Fitriyanah, Dwi Nur
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Jani, Yahya
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Abdullah, Kamaruddin
    Darma Persada University, Indonesia.
    Performance Study of Maximum Power Point Tracking (MPPT) Based on Type-2 Fuzzy Logic Controller on Active Dual Axis Solar Tracker2020In: E3S Web of Conferences, EDP Sciences, 2020, Vol. 190, p. 1-16, article id 00016Conference paper (Refereed)
    Abstract [en]

    World energy consumption increases with time, so that occur an energy imbalance. Many breakthroughs have developed to utilize renewable energy. The photovoltaic system is one of the easy-to-use renewable energies. The power conversion from PV fixed is still low, so the PV system is designed using the active dual-axis solar tracker. The PV tracker position can be adjusted to change the sun position to get maximum efficiency. The active dual-axis solar tracker system is integrated with the maximum power point tracking (MPPT) algorithm to keep PV operating at a maximum power point even though input variations change. The active dual-axis solar tracker system integrated with the maximum power point tracking (MPPT) algorithm to keep PV operating at a maximum power point even though input variations change. Tracking test simulation had done by comparing the output power of a fixed PV system with the active dual-axis solar tracker. Type-2 fuzzy logic based MPPT successfully increased the average output power by 10.48 % with the highest increase of 17.48 % obtained at 15:00 West Indonesia Time (GMT+7). The difference in power from a fixed PV system with the active dual-axis solar tracker of 36.08 W is from the output power worth 206.3 to 242.4 W. © The Authors, published by EDP Sciences, 2020.

  • 23.
    Abadi, Imam
    et al.
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Uyuniyah, Qurrotul
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Fitriyanah, Dwi Nur
    Institut Teknologi Sepuluh Nopember, Indonesia.
    Jani, Yahya
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM), Sweden.
    Abdullah, Kamaruddin
    Darma Persada University, Indonesia.
    Performance Study of Maximum Power Point Tracking (MPPT) Based on Type-2 Fuzzy Logic Controller on Active Dual Axis Solar Tracker2020In: E3S Web of Conferences, EDP Sciences , 2020, p. 1-16, article id 00016Conference paper (Refereed)
    Abstract [en]

    World energy consumption increases with time, so that occur an energy imbalance. Many breakthroughs have developed to utilize renewable energy. The photovoltaic system is one of the easy-to-use renewable energies. The power conversion from PV fixed is still low, so the PV system is designed using the active dual-axis solar tracker. The PV tracker position can be adjusted to change the sun position to get maximum efficiency. The active dual-axis solar tracker system is integrated with the maximum power point tracking (MPPT) algorithm to keep PV operating at a maximum power point even though input variations change. The active dual-axis solar tracker system integrated with the maximum power point tracking (MPPT) algorithm to keep PV operating at a maximum power point even though input variations change. Tracking test simulation had done by comparing the output power of a fixed PV system with the active dual-axis solar tracker. Type-2 fuzzy logic based MPPT successfully increased the average output power by 10.48 % with the highest increase of 17.48 % obtained at 15:00 West Indonesia Time (GMT+7). The difference in power from a fixed PV system with the active dual-axis solar tracker of 36.08 W is from the output power worth 206.3 to 242.4 W. 

  • 24.
    Abadir Guirgis, Georg
    Linköpings Universitet.
    Ecodriving på SJ: förarperspektiv på tekniska hjälpmedel för beslutsfattande och utbildning i Ecodriving2013Report (Other academic)
    Abstract [en]

    Even though all trips with SJ trains in Sweden are labeled “Bra Miljöval” (Good environmental choice), the requirements for reduced emissions and energy usage are constantly increased. Thus, SJ has to constantly develop their environmental profile. To investigate potential energy savings, SJ developed an education program in energy efficient driving (Eco-driving) and also let some of their train drivers use a technical tool supporting eco-driving. This report includes two studies. A critical review of the experimental study conducted by SJ and a complementary study based on observations of the education in energy efficient driving, along with interviews with the train drivers that participated in SJs experimental study. The experimental study provided valuable results, suggesting that energy savings through driver training and support are feasible. At the same time, there are contingencies in the collected energy data, making it difficult to draw any definite conclusions. The results of the interviews with the drivers show that there are ambiguities about what risks and consequences a future introduction of the technical tool for eco-driving could imply. Altogether, there are reasons to conduct further studies on how to best introduce energy-efficient driving in railway traffic as a whole.

    Download full text (pdf)
    FULLTEXT01
  • 25.
    Abali, B. Emek
    Technische Universität Berlin.
    Damage Formulation in Generalized Mechanics Based on a Variational Formulation2021In: Proceedings of the International scientific symposium on problems of the mechanics of deformable bodies: dedicated to the 110th anniversary from the birthday of A. A. ILYUSHIN / [ed] Brovko, G. L., Georgievskii, D. V. & Molodtsov, I. N., Moscow: Moscow State University Press, 2021, p. 350-357Conference paper (Refereed)
    Abstract [en]

    Damage mechanics is often modeled by using adhoc or phenomenological methodologies, which is useful but challenging to generalize. Especially inapplications with several length scales, a homogenization procedure leads to ametamaterial to be modeled by the generalized mechanics. We aim for a unifiedtheory of generalized damage mechanics by following a variation purelyalformulation.

  • 26.
    Abali, Bilen Emek
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    An Introduction to Piezoelectric and Thermoelectric Materials2022In: Handbook of Energy Materials / [ed] Ram Gupta, Singapore: Springer, 2022, p. 1-18Chapter in book (Refereed)
    Abstract [en]

    Materials may demonstrate electromagnetism and thermomechanics coupling. Although we benefit from this coupling in our modern lives, comprehending this coupling is challenging. We intuitively understand that temperature increase causes an expansion in polymers and alloys. Typical example is a plastic water bottle left in the sun, the expansion is visible by naked eyes. Yet it is more abstract to consider that an electric field may create a deformation or even a temperature change. Electromagnetic fields are more abstract since our senses fail to be sensitive to these physical quantities. There are indeed materials with so-called piezoelectric and pyroelectric properties and we use them for sensors and actuators. More confusingly, there is a thermoelectric effect relating electric current and heat flux. In order to set the ideas correctly, we explain these phenomena and introduce to the abstract world of electromagnetism and thermomechanics coupling. Furthermore, we provide an inside look to realize how different types of thermal and electric coupling phenomena work and how to model such materials adequately.

  • 27.
    Abali, Bilen Emek
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Asymptotic homogenization and parameter determination in metamaterials2021Conference paper (Other academic)
  • 28.
    Abali, Bilen Emek
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Energy based methods applied in mechanics by using the extended Noether's formalism2023In: Zeitschrift für angewandte Mathematik und Mechanik, ISSN 0044-2267, E-ISSN 1521-4001, Vol. 103, no 12Article in journal (Refereed)
    Abstract [en]

    Physical systems are modeled by field equations; these are coupled, partial differential equations in space and time. Field equations are often given by balance equations and constitutive equations, where the former are axiomatically given and the latter are thermodynamically derived. This approach is useful in thermomechanics and electromagnetism, yet challenges arise once we apply it in damage mechanics for generalized continua. For deriving governing equations, an alternative method is based on a variational framework known as the extended Noether's formalism. Its formal introduction relies on mathematical concepts limiting its use in applied mechanics as a field theory. In this work, we demonstrate the power of extended Noether's formalism by using tensor algebra and usual continuum mechanics nomenclature. We demonstrate derivation of field equations in damage mechanics for generalized continua, specifically in the case of strain gradient elasticity.

    Download full text (pdf)
    fulltext
  • 29.
    Abali, Bilen Emek
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Aldakheel, Fadi
    Zohdi, Tarek I.
    Multiphysics Computation of Thermomechanical Fatigue in Electronics Under Electrical Loading2022In: Current Trends and Open Problems in Computational Mechanics / [ed] Fadi Aldakheel, Blaž Hudobivnik, Meisam Soleimani, Henning Wessels, Christian Weißenfels, Michele Marino, Cham: Springer Nature, 2022, p. 1-14Chapter in book (Refereed)
  • 30.
    Abali, Bilen Emek
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics. Institute of Mechanics, MS 2, Technische Universität Berlin, Einsteinufer 5, 10587, Berlin, Germany.
    Barchiesi, Emilio
    Additive manufacturing introduced substructure and computational determination of metamaterials parameters by means of the asymptotic homogenization2021In: Continuum Mechanics and Thermodynamics, ISSN 0935-1175, E-ISSN 1432-0959, Vol. 33, no 4, p. 993-1009Article in journal (Refereed)
    Abstract [en]

    Metamaterials exhibit materials response deviation from conventional elasticity. This phenomenon is captured by the generalized elasticity as a result of extending the theory at the expense of introducing additional parameters. These parameters are linked to internal length scales. Describing on a macroscopic level, a material possessing a substructure at a microscopic length scale calls for introducing additional constitutive parameters. Therefore, in principle, an asymptotic homogenization is feasible to determine these parameters given an accurate knowledge on the substructure. Especially in additive manufacturing, known under the infill ratio, topology optimization introduces a substructure leading to higher-order terms in mechanical response. Hence, weight reduction creates a metamaterial with an accurately known substructure. Herein, we develop a computational scheme using both scales for numerically identifying metamaterials parameters. As a specific example, we apply it on a honeycomb substructure and discuss the infill ratio. Such a computational approach is applicable to a wide class substructures and makes use of open-source codes; we make it publicly available for a transparent scientific exchange.

    Download full text (pdf)
    fulltext
  • 31.
    Abali, Bilen Emek
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics. Institute of Mechanics Technische Universität Berlin Einsteinufer 5 Berlin 10967 Germany.
    Klunker, Andre
    Institute of Mechanics Technische Universität Berlin Einsteinufer 5 Berlin 10967 Germany.
    Barchiesi, Emilio
    International Research Center on Mathematics and Mechanics of Complex Systems Università degli Studi dell'Aquila Via Giovanni Gronchi 18 ‐ Zona industriale di Pile L'Aquila 67100 Italy.
    Placidi, Luca
    Engineering Faculty International Telematic University Uninettuno Corso Vittorio Emanuele II Rome 39 00186 Italy.
    A novel phase‐field approach to brittle damage mechanics of gradient metamaterials combining action formalism and history variable2021In: Zeitschrift für angewandte Mathematik und Mechanik, ISSN 0044-2267, E-ISSN 1521-4001, Vol. 101, no 9, article id e202000289Article in journal (Refereed)
    Abstract [en]

    Metamaterials response is generally modeled by generalized continuum based theories. Their inherent substructure leads to a necessity for higher-order theories, and especially in damage mechanics, such a generalization is difficult to acquire. We exploit the action formalism in order to obtain the governing equations in generalized damage mechanics for metamaterials. Additionally, by using auxilliary variables, the variational formulation is endowed with the first rate of damage variable that is missing in standard approaches. The presented action formalism with auxilliary variables leads directly to the weak form. We implement a finite element method based approach by using open-source computing platform called FEniCS and solve this weak in order to obtain the deformation and damage numerically. Metamaterials simulations are demonstrated for simple geometries in mixed mode (I and II) as well as in mode III.

    Download full text (pdf)
    fulltext
  • 32.
    Abali, Bilen Emek
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Vazic, Bozo
    Univ Utah, Dept Mech Engn, Salt Lake City, UT USA..
    Newell, Pania
    Univ Utah, Dept Mech Engn, Salt Lake City, UT USA..
    Influence of microstructure on size effect for metamaterials applied in composite structures2022In: Mechanics research communications, ISSN 0093-6413, E-ISSN 1873-3972, Vol. 122, article id 103877Article in journal (Refereed)
    Abstract [en]

    Microstructure related deviation from elastic response is known as "size-effect."Metamaterials - for example modeled by strain gradient elasticity - capture this effect adequately by means of additional parameters to be determined. We employ a methodology based on asymptotic homogenization in order to obtain metamaterials parameters and then present the influence of these additional parameters by using simulations. By means of the finite element method, we solve metamaterials deformation modeled by the strain gradient elasticity. The implementation is established by open-source packages (FEniCS) for a realistic, composite structure with round and oval inclusions.

    Download full text (pdf)
    fulltext
  • 33.
    Abas, N.
    et al.
    University of Gujrat, Hafiz Hayat Campus, Gujrat, Pakistan.
    Kalair, A. R.
    COMSATS University Islamabad, Islamabad, Pakistan.
    Seyedmahmoudian, M.
    Swinburne University, Australia.
    Naqvi, M.
    Karlstad University.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Khan, N.
    COMSATS University Islamabad, Islamabad, Pakistan.
    Dynamic simulation of solar water heating system using supercritical CO2 as mediating fluid under sub-zero temperature conditions2019In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 161, article id 114152Article in journal (Refereed)
    Abstract [en]

    CO2 is becoming increasingly important as a mediating fluid, and simulation studies are indispensable for corresponding developments. In this study, a simulation-based performance investigation of a solar water heating system using CO2 as a mediating fluid under sub-zero temperature condition is performed using the TRNSYS® software. The maximum performance is achieved at a solar savings fraction of 0.83 during July. The as lowest solar savingss fraction of 0.41 is obtained during December. The annual heat production of the proposed system under Fargo climate is estimated to be about 2545 kWh. An evacuated glass tube solar collector is designed, fabricated and tested for various climate conditions. Moreover, a detailed comparison of the system's performance at sub/supercritical and supercritical pressures shows that the annual heat transfer efficiency of the modeled system is 10% higher at supercritical pressure than at sub/supercritical pressures. This result can be attributd to the strong convection flow of CO2 caused by density inhomogeneities, especially in the near critical region. This condition resuls in high heat transfer rates.

  • 34.
    Abbas, Anwar
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Faruk Acar, Ömer
    Mälardalen University, School of Innovation, Design and Engineering.
    Simulation as an Enabler for ProductionSystem Development within the Indoor Vertical Farming Industry2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the increase in food consumption, new ideas, and technologies began to be developed. Inaddition, the developments generated by Industry 4.0 technologies have started to be applied tothe entire manufacturing sector and the indoor farming industry, which is currently trending.Many studies and articles have been prepared on this subject, and the main goal of each study isto produce quality products and to ensure continuity in production to cover the nonendingincrease in demand.

    This paper discusses how simulation technology, which is one of the industry 4.0 technologies,can be used in the production system development of the indoor farming industry. According tomany researchers, the biggest obstacle for the vertical farming industry is start-up cost, andsimulation technologies can be the solution for this since it allows future production systems tobe analyzed without any investment. To have a clear vision of how these technologies can beadapted in the indoor farming industry, this paper will find the answers to these questions, RQ1:How can simulation facilitate production system development and Industry 4.0 projects withinthe indoor farming industry? RQ2: What are the benefits and challenges when using simulationas a tool for production system development within the indoor farming industry? To reach thegoal of this paper, the case study method was used, and an indoor farming company was selectedto get more realistic data about the vertical farming system. BlueRedGold AB is a start-upcompany in the indoor farming industry, and it has a huge growth potential since they aim totransform its current production lines to be fully automated. Many articles and studies were usedto approach the solution of the research questions from a more technical and academic point ofview, and the analysis of these articles was carried out with the structured literature review method.

    After conducting this research, answers have been obtained for the research questions. Theauthors' solution to the layout issue, one of the case company's main challenges as indicated inthis study, was developed after extensive simulation model testing. As highlighted in this paper,it has been stated by many researchers, there are several simulation approaches to follow.However, the authors have developed a simulation modeling approach to be followed in theindoor vertical farming industry to overcome the complexity of these systems as well as thesimulation program complexity. In addition, several challenges and benefits have beenhighlighted in this paper such as the lack of ready models of the equipment used in indoorfarming which requires a knowledge of a programing language to overcome. Finally, despitechallenges, simulation technology can provide an applicable solution for production systemproblems of vertical farming companies/organizations to obtain continuous improvementphilosophy which is the main principle of Lean thinking. The generated simulation model in thisthesis project was successfully implemented, demonstrating how this technology might be aneffective solution for complex production systems as in the indoor farming sector. 

    Download full text (pdf)
    fulltext
  • 35. Abbas, Ghazanfar
    et al.
    Chaudhry, M. Ashraf
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Singh, Manish
    Liu, Qinghua
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Qin, Haiying
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Study of CuNiZnGdCe-Nanocomposite Anode for Low Temperature SOFC2012In: Nanoscience and Nanotechnology Letters, ISSN 1941-4900, Vol. 4, no 4, p. 389-393Article in journal (Refereed)
    Abstract [en]

    Composite electrodes of Cu0.16Ni0.27Zn0.37Ce0.16Gd0.04 (CNZGC) oxides have been successfully synthesized by solid state reaction method as anode material for low temperature solid oxide fuel cell (LTSOFC). These electrodes are characterized by XRD followed by sintering at various time periods and temperatures. Particle size of optimized composition was calculated 40-85 nm and sintered at 800 degrees C for 4 hours. Electrical conductivity of 4.14 S/cm was obtained at a temperature of 550 degrees C by the 4-prob DC method. The activation energy was calculated 4 x 10(-2) eV at 550 degrees C. Hydrogen was used as fuel and air as oxidant at anode and cathode sides respectively. I-V/I-P curves were obtained in the temperature range of 400-550 degrees C. The maximum power density was achieved for 570 mW/cm(2) at 550 degrees C.

  • 36.
    Abbas, Ghazanfar
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Ashfaq, M.
    Chaudhry, M. Ashraf
    Khan, Ajmal
    Ahmad, Imran
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Electrochemical study of nanostructured electrode for low-temperature solid oxide fuel cell (LTSOFC)2014In: International Journal of Energy Research, ISSN 0363-907X, E-ISSN 1099-114X, Vol. 38, no 4, p. 518-523Article in journal (Refereed)
    Abstract [en]

    Zn-based nanostructured Ba0.05Cu0.25Fe0.10Zn0.60O (BCFZ) oxide electrode material was synthesized by solid-state reaction for low-temperature solid oxide fuel cell. The cell was fabricated by sandwiching NK-CDC electrolyte between BCFZ electrodes by dry press technique, and its performance was assessed. The maximum power density of 741.87 mW-cm(-2) was achieved at 550 degrees C. The crystal structure and morphology were characterized by X-ray diffractometer (XRD) and SEM. The particle size was calculated to be 25 nm applying Scherer's formula from XRD data. Electronic conductivities were measured with the four-probe DC method under hydrogen and air atmosphere. AC Electrochemical Impedance Spectroscopy of the BCFZ oxide electrode was also measured in hydrogen atmosphere at 450 degrees C.

  • 37. Abbas, Ghazanfar
    et al.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. COMSATS Institute of Information Technology, Pakistan .
    Chaudhry, M. A.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Preparation and characterization of nanocomposite calcium doped ceria electrolyte with alkali carbonates (NK-CDC) for SOFC2010In: ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology, FUELCELL 2010, ASME Press, 2010, p. 427-432Conference paper (Refereed)
    Abstract [en]

    The entire world's challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid Oxide Fuel Cells (SOFCs) are believed to be the best alternative source which converts chemical energy into electricity without combustion. Nanostructured study is required to develop highly ionic conductive electrolyte for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O 1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M= Na and K) electrolyte was prepared by co-precipitation method in this study. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology was characterized by X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). The particle size was calculated in the range of 10-20nm by Scherrer's formula and compared with SEM and TEM results. The ionic conductivity was measured by using AC Electrochemical Impedance Spectroscopy (EIS) method. The activation energy was also evaluated. The performance of the cell was measured 0.567W/cm2 at temperature 550°C with hydrogen as a fuel.

  • 38.
    Abbas, Ghazanfar
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. COMSATS Institute of Information Technology, Pakistan.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. COMSATS Institute of Information Technology, Pakistan.
    Khan, M. Ajmal
    Ahmad, Imran
    Chaudhry, M. Ashraf
    Sherazi, Tauqir A.
    Mohsin, Munazza
    Ahmad, Mukhtar
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Synthesize and characterization of nanocomposite anodes for low temperature solid oxide fuel cell2015In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 40, no 1, p. 891-897Article in journal (Refereed)
    Abstract [en]

    Solid oxide fuel cells have much capability to become an economical alternative energy conversion technology having appropriate materials that can be operated at comparatively low temperature in the range of 400-600 degrees C. The nano-scale engineering has been incorporated to improve the catalytic activity of anode materials for solid oxide fuel cells. Nanostructured Al0.10NixZn0.90-xO oxides were prepared by solid state reaction, which were then mixed with the prepared Gadolinium doped Ceria GDC electrolyte. The crystal structure and surface morphology were characterized by XRD and SEM. The particle size was evaluated by XRD data and found in the range of 20-50 nm, which was then ensured by SEM pictures. The pellets of 13 mm diameter were pressed by dry press technique and electrical conductivities (DC and AC) were determined by four probe techniques and the values have been found to be 10.84 and 4.88 S/cm, respectively at hydrogen atmosphere in the temperature range of 300-600 degrees C. The Electrochemical Impedance Spectroscopy (EIS) analysis exhibits the pure electronic behavior at hydrogen atmosphere. The maximum power density of ANZ-GDC composite anode based solid oxide fuel cell has been achieved 705 mW/cm(2) at 550 degrees C.

  • 39.
    Abbas, Maryam
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Knowledge Management vid uppdragsarbete2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 40.
    Abbas, Nada
    et al.
    Linnaeus University, Faculty of Technology, Department of Informatics.
    Kans, Mirka
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering. Chalmers University of Technology, Sweden.
    Information Needs of Gravel Road Stakeholders2022In: Infrastructures, E-ISSN 2412-3811, Vol. 7, no 12, article id 166Article in journal (Refereed)
    Abstract [en]

    Within any ecosystem, information sharing is essential. In this paper, the Swedish gravel road ecosystem is studied, where information plays a crucial role for the effective management of operations and maintenance. However, efficient information sharing is not enabled due to the lack of appropriate information systems. For addressing this issue, this paper intends to elicit information needs of gravel road stakeholders to support the design of a cloud-based information system. The main purpose is to explore the information needs of stakeholders within the Swedish gravel road ecosystem. Data were collected through in-depth semi-structured interviews with 11 participants representing key stakeholders in the ecosystem. Template analysis was used for analyzing the interview results. The major findings were a set of information needs covering road identification and condition, weather conditions, accessibility and traffic, maintenance policy, and sensor data. The results form a comprehensive information model for the further development of a cloud-based gravel road management system that would contribute to increased traffic safety and comfort, lower maintenance and management costs, and better decision-making abilities.

    Download full text (pdf)
    fulltext
  • 41.
    abbas, Noah Wessam
    et al.
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management. Jönköping University, School of Engineering, JTH, Supply Chain and Operations Management. UofSC.
    Sheikh Osman, Jegar
    Jönköping University, School of Engineering, JTH, Industrial Engineering and Management. Jönköping University, School of Engineering, JTH, Supply Chain and Operations Management.
    Production Flow Improvements in a Mixed-Model Assembly Line - A Case study at a large manufacturing plant2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to improve the production flow in a mixed-model assembly line. This has been achieved by first identifying the problems in a mixed-model assembly line and proposing the solutions that can be applied to the problems. In addition, the purpose will be fulfilled with the help of the existing studies and by answering the research questions.

  • 42.
    Abbas Sohani, Amir
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Waste heat recovery from SSAB’s Steel plant in Oxelösund using a Heat Pump2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project was focused on waste heat potentials in the iron and steel industry. High temperature industrial heat pumps (HTIHP) for medium temperature, waste heat recovery were modelled. The SSAB iron and steel plant in Oxelösund was used as an example. The iron and steel industry in Sweden is a large energy consumer, together with the pulp and paper industry. There is also a large potential for waste heat recovery in the steel industry. This is already done in for instance Luleå [1].

    Iron and steel production methods and waste heat recovery in the world, especially in the US and Sweden, have been reviewed in a literature study. Current methods and potentials of waste heat recovery in the iron and steel industry of Sweden were especially reviewed. The SSAB iron and steel plant in Oxelösund has been planning for decades, not only to heat the city of Oxelösund as today, but also to expand to the nearby city of Nyköping 12 km away [2].

    Typically the maximum temperature entering the district heating network of Nyköping would be 110 °C on the coldest day. The heat pump output from a waste heat recovery plant generally does not have to reach such a high temperature. However, 80 °C maximum forward temperature would surely be enough to use recovered heat all the time. Even a lower temperature like 75 °C would probably be sufficient – as only a few heat exchangers in individual houses then would have to be changed, to accept that lower temperature. The extra degrees between 80 °C (75 °C) and 110 °C can be taken with heat from e.g. existing biofuel furnaces locally in Nyköping.

    Using heat pumps in this context is not self-evident. Generally the heat flows from a steel plant are available at such high temperatures that no heat pump ideally is needed. However collecting the heat at those high temperatures, in an old plant, can get very expensive and interfere with the processes. Therefore the study is focusing on medium temperature (30 – 40 °C) waste heat potentials implementing High Temperature Industrial Heat Pumps (HTIHP). The heat is now being rejected by a cooling tower. That way, easily available waste heat, can cover 50% of the total need from Nyköping. Assuming a COP of around 5 and adding the electricity needed to run the heat pump, the total will result in totally 62% of the energy need for Nyköping.

    The Oxelösund Plant is just an example and the study is really focusing on HITIHP for this and similar purposes. Appropriate components and refrigerants have been evaluated and the general layouts of proper HITIHP types are suggested. A literature study on the best choice of refrigerant in the high temperature heat pump has been done.

    A two stage high temperature heat pump has been modeled and simulated using the available heat sink capacity and temperature, together with the demanded temperatures in the district heating network. The simulation has mainly been performed using the EES software. R245fa is e.g. a good candidate as refrigerant in a second stage (high temperature stage) of a two stage cascade heat pump. With R245fa even higher temperatures than 90°C to the district heating can be achieved. Earlier, R134a would be used in this application but R245fa has e.g. a lower GWP (around 1000 instead of around 1300) [3]. Many different refrigerants have been simulated in the first of two stages of a smaller screw compressor driven cascade heat pump. Also a two stage turbo compressor throttling heat pump, using a flash tank, has been simulated, showing a good performance. In the latter case both, refrigerants R1234ze(z) and R245fa have good characteristics but R1234ze(z) has a much lower GWP.

    All COPs, compressor energy consumptions, condenser pressures, pressure ratios were compared. R245fa-R245fa and R600-R245fa were studied in the two stage cascade systems. They came out with the best results. R717-R245fa also showed a very good performance, but had other limitations. In two stage flash tank systems, R1234ze(z) had the best performance (COP) and no temperature loss between the two stages (like in the cascade systems). If SSAB Oxelösund’s blast furnace and cooling tower water would not be available, the turbo heat pump can produce the demanded heat, using sea water as heat source instead.

    The CO2 emission reduction is very hard to calculate. That will be more of a political conviction problem. A very rough cost estimation of the projects investment cost is also done. It will cost between 420 and 450 MSEK. This cost estimation includes a heat pump and 12 km pipe to Nyköping. The cost of heat delivered in Nyköping will vary between 0,2 and 0,65 SEK/kWh when the cost of electricity is varied between 0,5 and 2 SEK/kWh (include taxes). In that price the capital costs for the heat pump and pipe is included. The high cost level 0, 65 SEK/kWh assumes that sea water is used as heat source.

    A cooling towers waste heat can be recovered, using a high temperature heat pump. This heat can thus be delivered from Oxelösund to Nyköping. The economic viability of this idea is only superficially covered. Factors like if the old furnace in Nyköping needs upgrading, which could be postponed, could possibly tip the project into go. Maitenance cost, of the existing cooling tower, is another such factor, initiating the project. A waste heat pipe between Oxelösund and Nyköping has been studied at least since the middle of the 1970:s by e.g. Lars Åke Cronholm [4]. Could it be the right time now?

    Download full text (pdf)
    fulltext
  • 43.
    Abbas, Tabassom
    et al.
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Sandblom, Sofia
    University West, Department of Engineering Science, Division of Industrial Engineering and Management, Electrical- and Mechanical Engineering.
    Digitalisering av arbetsflöde för avvikelsehantering på inköpt material: En fallstudie utförd på Nolato Cerbo AB i Trollhättan2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A case study was performed at Nolato Cerbo AB in Trollhättan, with the objective to design a suggestion of a digital workflow for deviation handlingfor purchased material. The following questions were issued to fulfil the objective of the case study:

    • Is a workflow for deviation handling for purchased material possible to digitalize in order to facilitate documentation, traceability and information handling?

    • How should the workflow be designed in order to reach the involved personnel's requirements and needs?

    • Which advantages and disadvantages could emerge from the implementation of a digital workflow? To be able to map the current workflow and its issues, interviews with the involved departments were conducted. The interviews also brought up the employees' opinions of a digital workflow. A flowchart was created and waste in the workflow was identified. A benchmarking was performed at Varner Retail Logistics AB, to get an insight of how another company uses a digital workflow for deviation handling. A new flowchart for deviation handling for purchased material was created, where the manual parts of the flow were digitalized. After a test had been performed with concerned employees, it could be stated that the digital workflow will facilitate documentation, traceability and information handling. The requirements and needs for the involved personnel were also fulfilled. Advantages that the respondents consider can be achieved with the digital workflow was time save, no manual handling of paper, a faster distribution of information and that the correct information will be filled in from the beginning. Disadvantages that the respondents consider can emerge is that it will take some time for the employees to learn and adapt to the new way of working and the limitations of the mobileapplication. The conclusions that were drawn was that the digital workflow will be able to be used if it's designed according to the suggestion, although changes to the workflow might be performed in the future. There might also be employees at Nolato CerboAB which afraid of digitalization and changes. For the implementation to be successful, an education and information about the possibilities that digitalization brings will be required.

    Download full text (pdf)
    fulltext
  • 44.
    Abbas, Taimoor
    et al.
    Lund Univ, Elect & Informat Technol Dept, S-22100 Lund, Sweden..
    Sjöberg, Katrin
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Kåredal, Johan
    Lund Univ, Elect & Informat Technol Dept, S-22100 Lund, Sweden..
    Tufvesson, Fredrik
    Lund Univ, Elect & Informat Technol Dept, S-22100 Lund, Sweden..
    A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations2015In: International Journal of Antennas and Propagation, ISSN 1687-5869, E-ISSN 1687-5877, article id 190607Article in journal (Refereed)
    Abstract [en]

    The vehicle-to-vehicle (V2V) propagation channel has significant implications on the design and performance of novel communication protocols for vehicular ad hoc networks (VANETs). Extensive research efforts have been made to develop V2V channel models to be implemented in advanced VANET system simulators for performance evaluation. The impact of shadowing caused by other vehicles has, however, largely been neglected in most of the models, as well as in the system simulations. In this paper we present a shadow fading model targeting system simulations based on real measurements performed in urban and highway scenarios. The measurement data is separated into three categories, line-of-sight (LOS), obstructed line-of-sight (OLOS) by vehicles, and non-line-of-sight due to buildings, with the help of video information recorded during the measurements. It is observed that vehicles obstructing the LOS induce an additional average attenuation of about 10 dB in the received signal power. An approach to incorporate the LOS/OLOS model into existing VANET simulators is also provided. Finally, system level VANET simulation results are presented, showing the difference between the LOS/OLOS model and a channel model based on Nakagami-m fading.

  • 45.
    Abbas, Umar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Management and Mechanical Engineering.
    Barnets bästa – en utveckling inom Kriminalvården: En fallstudie om hur kriminalvården utvecklar sin verksamhet efter att barnkonventionen blev lag i Sverige.2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The starting point for the study was that the Swedish Prison and Probation Service received criticism from the Committee on the Rights of the Child when it comes to children of parents who are deprived of their liberty, criticism that children travel far to visit their parents, and criticism that children who travel far may not automatically extend their visit to certain institutions. At the same time, research has pointed to challenges and important conditions for considering the Convention on the Rights of the Child in the prison service. In a Swedish context, after the Convention on the Rights of the Child becomes law in Sweden in 2020, the organizational development with regard to fulfilling children's rights in the public sector has been relatively unexplored. The research aims to fill part of that knowledge gap. The purpose of the study is to see how the Swedish Prison and Probation Service develops with regard to compliance with the Convention on the Rights of the Child. The issues focus on how the prison service improves its activities in order to constantly consider the Convention on the Rights of the Child in matters concerning children. The study was conducted through a qualitative study. Data collection for this study was done through semi-structured interviews, nine respondents who are children's representatives at different levels in the hierarchy in the region west. The study shows that the Swedish Prison and Probation Service controls processes centrally from above by informing legislation, national guidelines for communicating how the Convention on the Rights of the Child is taken into account to regions and then to local units. Then each unit interprets the guidelines in the way that suits the unit type, such as detention, institution, or probation. The study shows that more cooperation is needed between different authorities to promote work for the best interests of the child. According to the study, however, it is not enough to consider children's conventions in the handbooks or through training, but there must be a personal commitment on the part of employees considered customer-oriented.

    Download full text (pdf)
    fulltext
  • 46.
    Abbas, Wasim
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Asghar, Imran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    The Role of Leadership In Organizatinal Change: Relating the successful Organizational Change with Visionary and Innovative Leadership2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The globalization has converted the world into a small global village; a village in which there is an ever high stream of contentions and competitions between organizations. In this scenario the most effective and beneficial maneuver for any organization is to create innovative ways in conducting business. This thesis deals with the role of leadership in the phenomena of organizational change and innovation. The leader as a person in charge or as a change agent can manage an organization or the process of organizational change more effectively and successfully if h/she is capable and competent. Rapid technological advancements, high expectations of customers, and ever changing market situations have compelled organizations to incessantly reassess and reevaluate how they work and to understand, adopt and implement changes in their business model in response of changing trends. Organizational change is a demand of the day, and needed for organizations to survive. Organizations now a days, well understand the importance of the matter, and are serious to prepare themselves not only the current, but also for the future trends to get the level of sustainable success, but Along with all of its implications and importance the process of organizational change is also a very complex and challenging.  Research shows that 70 percent of organizational changes fail to get their goals. As leadership has a central role in evolution and cultivating an organization, the process of organizational change demands a very effective and highly competent leadership that is well capable to perceive the most desirable shape of an organization and address the issue of organizational change in most appropriate way. The analysis of literature reviewed and the results of real life cases of organizations which are studied for this thesis shows, that a leadership with the competencies of “Vision” and “Innovative Approach” along with other characteristics can prove more effective to conclude the complex phenomena of organizational change with success. Further the successful organizational change can leads to innovation for organization, which is the key of long term success and sustainability. This thesis as a result proposed a model which is derived from the leadership competencies, organizational change, and sustainable success and innovation literature. This model expresses relationship between successful organizational change and leadership on the basis of h/her characteristics, which are ‘Vision” and “Innovative Approach”. With the help of proposed model this relationship can be viewed graphically.

    Download full text (pdf)
    FULLTEXT01
  • 47. Abbasi Hoseini, A.
    et al.
    Lundell, Fredrik
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Andersson, H. I.
    Finite-length effects on dynamical behavior of rod-like particles in wall-bounded turbulent flow2015In: International Journal of Multiphase Flow, ISSN 0301-9322, E-ISSN 1879-3533, Vol. 76, p. 13-21Article in journal (Refereed)
    Abstract [en]

    Combined Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV) measurements have been performed in dilute suspensions of rod-like particles in wall turbulence. PIV results for the turbulence field in the water table flow apparatus compared favorably with data from Direct Numerical Simulations (DNS) of channel flow turbulence and the universality of near-wall turbulence justified comparisons with DNS of fiber-laden channel flow. In order to examine any shape effects on the dynamical behavior of elongated particles in wall-bounded turbulent flow, fibers with three different lengths but the same diameter were used. In the logarithmic part of the wall-layer, the translational fiber velocity was practically unaffected by the fiber length l. In the buffer layer, however, the fiber dynamics turned out to be severely constrained by the distance z to the wall. The short fibers accumulated preferentially in low-speed areas and adhered to the local fluid speed. The longer fibers (l/z > 1) exhibited a bi-modal probability distribution for the fiber velocity, which reflected an almost equal likelihood for a long fiber to reside in an ejection or in a sweep. It was also observed that in the buffer region, high-speed long fibers were almost randomly oriented whereas for all size cases the slowly moving fibers preferentially oriented in the streamwise direction. These phenomena have not been observed in DNS studies of fiber suspension flows and suggested l/z to be an essential parameter in a new generation of wall-collision models to be used in numerical studies.

  • 48.
    Abbasi, S.
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Particle emissions from rail vehicles: A review2012In: Civil-Comp Proceedings, ISSN 1759-3433, Vol. 98Article in journal (Refereed)
    Abstract [en]

    Emission of airborne particles is a side effect from rail transport. This paper reviews recent research on particle emissions from rail vehicles. Both exhaust and non-exhaust particle emissions are characterized by size, morphology, composition, and size distribution. Current legislation, knowledge of adverse health effects, and available and proposed solutions for emission reductions are also treated. There has been much focus on exhaust emissions, but only a few limited studies have investigated non-exhaust particle emissions, which contain a significant amount of metallic materials. A new method for measuring the airborne wear particle emission rate (AWPER) is proposed as a first step to guide new legislations and to focus further research on non-exhaust airborne emission, i.e., research on the generation mechanisms for particle emissions and their adverse health effects. 

  • 49.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A comparison between particle characteristics between two railway brake pads2013Report (Other academic)
  • 50.
    Abbasi, Saeed
    Sharif university of Technology, Iran.
    A feasibilty study to establish freight cars overhaul center (Master thesis), Sharif university of technology2005Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
1234567 1 - 50 of 51065
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf